1. Technical Field
The present invention relates to a method for manufacturing a crystal device, and more specifically to a method for manufacturing a crystal device that can be made more easily.
2. Related Art
Conventionally, crystal oscillators are widely used as a source of clock signals in various electronic devices. The oscillation frequency of a crystal oscillator is determined by the resonance frequency of the crystal unit contained in the crystal oscillator. Examples of these crystal units include a convex or bevel crystal piece with a thickness increasing toward its center, prepared by the edges of an AT-cut crystal plate being processed to be curved surfaces. For example, JP-A-11-298278 discloses a convex crystal piece. These convex or bevel crystal units have a thick central portion to concentrate the vibration in the central portion of their crystal pieces, making efficient vibration with less energy possible. Also, in general, crystal units (i.e., crystal pieces) with the aforementioned shape are manufactured by polishing.